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Maciej Jarosz - One of the best experts on this subject based on the ideXlab platform.
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novel methodology for the extraction and identification of natural dyestuffs in historical textiles by hplc uv vis esi ms case study chasubles from the wawel cathedral collection
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Katarzyna Lech, Maciej JaroszAbstract:High-performance liquid chromatography coupled with spectrophotometric and electrospray mass spectrometric detection (HPLC–UV–Vis–ESI MS) was used for characterization of natural dyes present in historical art works. The gradient program was developed for identification of 29 colorants of various polarities. Dual detection system (UV–Vis and ESI MS) allowed differentiation of all compounds, even if they were not completely separated. This enabled examination of more color compounds over a substantially shorter time in comparison with previously recommended methods. Moreover, for extraction of colorants from historical textiles a two-step sequential procedure was proposed, excluding evaporation used in earlier procedures. The developed method was successfully applied to identification of indigotin, carminic, kermesic, flavokermesic, dcII, dcIV, dcVII, and ellagic acids as well as luteolin, apigenin, and genistein in red, violet, and green fibers taken from three selected historical chasubles which belong to the collection of the Wawel Cathedral treasury (Cracow, Poland). Italian textiles from the fifteenth and sixteenth centuries, of which chasubles were made, were dyed with a limited number of dyestuffs, consistently used for all batches of fabrics. The obtained results also allowed confirmation of the structure of the so-called “dcII” component of cochineal as a C-Glucose Derivative of flavokermesic acid.
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Novel methodology for the extraction and identification of natural dyestuffs in historical textiles by HPLC–UV–Vis–ESI MS. Case study: chasubles from the Wawel Cathedral collection
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Katarzyna Lech, Maciej JaroszAbstract:High-performance liquid chromatography coupled with spectrophotometric and electrospray mass spectrometric detection (HPLC–UV–Vis–ESI MS) was used for characterization of natural dyes present in historical art works. The gradient program was developed for identification of 29 colorants of various polarities. Dual detection system (UV–Vis and ESI MS) allowed differentiation of all compounds, even if they were not completely separated. This enabled examination of more color compounds over a substantially shorter time in comparison with previously recommended methods. Moreover, for extraction of colorants from historical textiles a two-step sequential procedure was proposed, excluding evaporation used in earlier procedures. The developed method was successfully applied to identification of indigotin, carminic, kermesic, flavokermesic, dcII, dcIV, dcVII, and ellagic acids as well as luteolin, apigenin, and genistein in red, violet, and green fibers taken from three selected historical chasubles which belong to the collection of the Wawel Cathedral treasury (Cracow, Poland). Italian textiles from the fifteenth and sixteenth centuries, of which chasubles were made, were dyed with a limited number of dyestuffs, consistently used for all batches of fabrics. The obtained results also allowed confirmation of the structure of the so-called “dcII” component of cochineal as a C -Glucose Derivative of flavokermesic acid.
Katarzyna Lech - One of the best experts on this subject based on the ideXlab platform.
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novel methodology for the extraction and identification of natural dyestuffs in historical textiles by hplc uv vis esi ms case study chasubles from the wawel cathedral collection
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Katarzyna Lech, Maciej JaroszAbstract:High-performance liquid chromatography coupled with spectrophotometric and electrospray mass spectrometric detection (HPLC–UV–Vis–ESI MS) was used for characterization of natural dyes present in historical art works. The gradient program was developed for identification of 29 colorants of various polarities. Dual detection system (UV–Vis and ESI MS) allowed differentiation of all compounds, even if they were not completely separated. This enabled examination of more color compounds over a substantially shorter time in comparison with previously recommended methods. Moreover, for extraction of colorants from historical textiles a two-step sequential procedure was proposed, excluding evaporation used in earlier procedures. The developed method was successfully applied to identification of indigotin, carminic, kermesic, flavokermesic, dcII, dcIV, dcVII, and ellagic acids as well as luteolin, apigenin, and genistein in red, violet, and green fibers taken from three selected historical chasubles which belong to the collection of the Wawel Cathedral treasury (Cracow, Poland). Italian textiles from the fifteenth and sixteenth centuries, of which chasubles were made, were dyed with a limited number of dyestuffs, consistently used for all batches of fabrics. The obtained results also allowed confirmation of the structure of the so-called “dcII” component of cochineal as a C-Glucose Derivative of flavokermesic acid.
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Novel methodology for the extraction and identification of natural dyestuffs in historical textiles by HPLC–UV–Vis–ESI MS. Case study: chasubles from the Wawel Cathedral collection
Analytical and Bioanalytical Chemistry, 2011Co-Authors: Katarzyna Lech, Maciej JaroszAbstract:High-performance liquid chromatography coupled with spectrophotometric and electrospray mass spectrometric detection (HPLC–UV–Vis–ESI MS) was used for characterization of natural dyes present in historical art works. The gradient program was developed for identification of 29 colorants of various polarities. Dual detection system (UV–Vis and ESI MS) allowed differentiation of all compounds, even if they were not completely separated. This enabled examination of more color compounds over a substantially shorter time in comparison with previously recommended methods. Moreover, for extraction of colorants from historical textiles a two-step sequential procedure was proposed, excluding evaporation used in earlier procedures. The developed method was successfully applied to identification of indigotin, carminic, kermesic, flavokermesic, dcII, dcIV, dcVII, and ellagic acids as well as luteolin, apigenin, and genistein in red, violet, and green fibers taken from three selected historical chasubles which belong to the collection of the Wawel Cathedral treasury (Cracow, Poland). Italian textiles from the fifteenth and sixteenth centuries, of which chasubles were made, were dyed with a limited number of dyestuffs, consistently used for all batches of fabrics. The obtained results also allowed confirmation of the structure of the so-called “dcII” component of cochineal as a C -Glucose Derivative of flavokermesic acid.
David D. Kitts - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of glycation reaction in tissue protein incubations by water soluble rutin Derivative
Molecular and Cellular Biochemistry, 2003Co-Authors: Takashi Nagasawa, Nobuaki Tabata, Naoyuki Nishizawa, Youichi Aiba, David D. KittsAbstract:In the Maillard reaction, nonenzymatic glycation reaction reversibly produces Amadori rearrangement products which subsequently lead to the formation of irreversible advanced glycation end-product (AGE). These reactions are important in the pathogenesis of complications associated with diabetes. This study examined the antioxidant activity of rutin and related efficacy to inhibit glycation in three distinct tissue protein sources. Rutin and the rutin analogue exhibited significant antioxidant activity in a liposomal model reaction similar to quercetin. Incubation of rat muscle and kidney proteins with 50 mM Glucose for 5 days resulted in the generation of N ^ε-fructoselysine (FL), a biomarker for initial stage glycation. The addition of G-rutin, a water soluble Glucose Derivative of rutin, to the incubation medium (0.1 mM) reduced (p < 0.05) FL production. AGE content in both muscle and kidney proteins was also increased (p < 0.05) with the addition of Glucose in the incubation mixture, but completely suppressed by the presence of G-rutin. On the contrary, inhibition of FL and AGE formation by G-rutin was found to be comparatively less effective in bovine serum albumin than both muscle and kidney proteins. These results demonstrate that the antioxidant activity of G-rutin corresponds to a strong affinity to suppress the formation of both initial and advanced stages of Maillard reaction in tissue protein sources.
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inhibition of glycation reaction in tissue protein incubations by water soluble rutin Derivative
Molecular and Cellular Biochemistry, 2003Co-Authors: Takashi Nagasawa, Nobuaki Tabata, Naoyuki Nishizawa, Youichi Aiba, Yoshiaki Ito, David D. KittsAbstract:In the Maillard reaction, nonenzymatic glycation reaction reversibly produces Amadori rearrangement products which subsequently lead to the formation of irreversible advanced glycation end-product (AGE). These reactions are important in the pathogenesis of complications associated with diabetes. This study examined the antioxidant activity of rutin and related efficacy to inhibit glycation in three distinct tissue protein sources. Rutin and the rutin analogue exhibited significant antioxidant activity in a liposomal model reaction similar to quercetin. Incubation of rat muscle and kidney proteins with 50 mM Glucose for 5 days resulted in the generation of N e-fructoselysine (FL), a biomarker for initial stage glycation. The addition of G-rutin, a water soluble Glucose Derivative of rutin, to the incubation medium (0.1 mM) reduced (p < 0.05) FL production. AGE content in both muscle and kidney proteins was also increased (p < 0.05) with the addition of Glucose in the incubation mixture, but completely suppressed by the presence of G-rutin. On the contrary, inhibition of FL and AGE formation by G-rutin was found to be comparatively less effective in bovine serum albumin than both muscle and kidney proteins. These results demonstrate that the antioxidant activity of G-rutin corresponds to a strong affinity to suppress the formation of both initial and advanced stages of Maillard reaction in tissue protein sources. (Mol Cell Biochem 249: 3–10, 2003)
J. Pohl - One of the best experts on this subject based on the ideXlab platform.
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D-19575—a sugar-linked isophosphoramide mustard Derivative exploiting transmembrane Glucose transport
Cancer Chemotherapy and Pharmacology, 1995Co-Authors: J. Pohl, B. Bertram, P. Hilgard, M. R. Nowrousian, J. Stüben, M. WießlerAbstract:D-19575 is a Glucose Derivative of ifosfamide mustard with a broad spectrum of antitumor activity in animal models. In comparison with ifosfamide, D-19575 is less toxic and is better tolerated by tumor-bearing animals, achieving a better therapeutic efficacy. D-19575 is directly cytotoxic in vitro—in contrast to ifosfamide— and it is possible to modulate this cytotoxicity by inhibition of transmembrane Glucose transporters. Correspondingly, renal reabsorption of filtered D-19575 could be blocked by pre- and cotreatment with phlorizin, resulting in a higher urinary excretion of the unchanged drug. The toxicity to white blood cells, colony-forming units (CFU-C), and spleen-cell colony-forming units (CFU-S) is considerably lower for D-19575 as compared with ifosfamide. In conclusion, D-19575 is a new alkylating cytotoxic agent with increased antitumor selectivity, probably caused by an active transmembrane transport mechanism.
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d 19575 a sugar linked isophosphoramide mustard Derivative exploiting transmembrane Glucose transport
Cancer Chemotherapy and Pharmacology, 1995Co-Authors: J. Pohl, B. Bertram, P. Hilgard, M. R. Nowrousian, J. Stüben, M WieslerAbstract:D-19575 is a Glucose Derivative of ifosfamide mustard with a broad spectrum of antitumor activity in animal models. In comparison with ifosfamide, D-19575 is less toxic and is better tolerated by tumor-bearing animals, achieving a better therapeutic efficacy. D-19575 is directly cytotoxic in vitro—in contrast to ifosfamide— and it is possible to modulate this cytotoxicity by inhibition of transmembrane Glucose transporters. Correspondingly, renal reabsorption of filtered D-19575 could be blocked by pre- and cotreatment with phlorizin, resulting in a higher urinary excretion of the unchanged drug. The toxicity to white blood cells, colony-forming units (CFU-C), and spleen-cell colony-forming units (CFU-S) is considerably lower for D-19575 as compared with ifosfamide. In conclusion, D-19575 is a new alkylating cytotoxic agent with increased antitumor selectivity, probably caused by an active transmembrane transport mechanism.
Akiharu Fujino - One of the best experts on this subject based on the ideXlab platform.
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in vitro metabolism of the glycosidic sweeteners stevia mixture and enzymatically modified stevia in human intestinal microflora
Food and Chemical Toxicology, 2003Co-Authors: E Koyama, Ken Kitazawa, Yuji Ohori, Osamu Izawa, Kazuyuki Kakegawa, Akiharu Fujino, Michio UiAbstract:Stevia mixture, sweeteners extracted from the leaves of Stevia rebaudiana Bertoni, consists mainly of stevioside and rebaudioside A (glycosides of the diterpene Derivative steviol). The aim of this study was to investigate human intestinal metabolism of stevia mixture and its a-Glucose Derivative (known in Japan as enzymatically modified stevia) by LC/MS/ESI analysis. Degradation was examined by incubating stevia mixture, enzymatically modified stevia, stevioside, rebaudioside A, a-monoglucosylstevioside, a-monoglucosylrebaudioside A and the aglycone, steviol with pooled human faecal homogenates (obtained from five healthy volunteers) for 0, 8 and 24 h under anaerobic conditions. Stevia mixture, enzymatically modified stevia, stevioside and rebaudioside A (0.2 mg/ml) were completely eliminated within 24 h, whereas no degradation of steviol (0.08 and 0.2 mg/ml) appeared to be found during the incubation period. Stevia mixture, stevioside and rebaudioside A appeared to be hydrolyzed to steviol by human intestinal microflora: this observation is consistent with previous rat metabolism studies. Similarly, enzymatically modified stevia appeared to be metabolized via stevia components and, finally, to steviol. This study suggests that there are apparently no species differences in intestinal metabolism of stevia mixture between rats and humans. # 2002 Elsevier Science Ltd. All rights reserved.
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in vitro metabolism of the glycosidic sweeteners stevia mixture and enzymatically modified stevia in human intestinal microflora
Food and Chemical Toxicology, 2003Co-Authors: E Koyama, Yuji Ohori, Osamu Izawa, Kazuyuki Kakegawa, Ke Kitazawa, Akiharu FujinoAbstract:Stevia mixture, sweeteners extracted from the leaves of Stevia rebaudiana Bertoni, consists mainly of stevioside and rebaudioside A (glycosides of the diterpene Derivative steviol). The aim of this study was to investigate human intestinal metabolism of stevia mixture and its alpha-Glucose Derivative (known in Japan as enzymatically modified stevia) by LC/MS/ESI analysis. Degradation was examined by incubating stevia mixture, enzymatically modified stevia, stevioside, rebaudioside A, alpha-monoglucosylstevioside, alpha-monoglucosylrebaudioside A and the aglycone, steviol with pooled human faecal homogenates (obtained from five healthy volunteers) for 0, 8 and 24 h under anaerobic conditions. Stevia mixture, enzymatically modified stevia, stevioside and rebaudioside A (0.2 mg/ml) were completely eliminated within 24 h, whereas no degradation of steviol (0.08 and 0.2 mg/ml) appeared to be found during the incubation period. Stevia mixture, stevioside and rebaudioside A appeared to be hydrolyzed to steviol by human intestinal microflora: this observation is consistent with previous rat metabolism studies. Similarly, enzymatically modified stevia appeared to be metabolized via stevia components and, finally, to steviol. This study suggests that there are apparently no species differences in intestinal metabolism of stevia mixture between rats and humans.